How to Calculate Your Macros for Weight Loss

Macros — short for macronutrients — are the three main sources of calories in food: protein (4 kcal per gram), carbohydrate (4 kcal per gram), and fat (9 kcal per gram). Calculating them starts with two prior figures: your total daily energy expenditure (often called TDEE or maintenance calories) and your intended calorie deficit.

Step 1 — Find your maintenance calories

Your maintenance calories represent the number of calories your body needs to hold its current weight. This is built from your basal metabolic rate (BMR) — the energy burned at complete rest — multiplied by an activity factor. How to work out your calorie intake is covered in detail in our dedicated guide, but in broad terms, most adults find their maintenance figure sits somewhere between roughly 1,600 and 3,000 kcal per day depending on size, age, sex, and activity level. Use an established formula (Mifflin–St Jeor is widely used) to get a starting estimate.

Step 2 — Apply a deficit

For weight loss, a common educational starting point is a deficit of 300–500 kcal below maintenance — enough to support steady progress without cutting so deep that muscle loss or fatigue become a problem. Your calorie and macro hub has more on choosing an appropriate deficit range. Because GLP-1 medicines already reduce appetite, many people find they are naturally eating at a deficit without much effort; the risk here is eating too little protein, not too much.

Step 3 — Set your protein target first

On a reduced-calorie GLP-1 journey, protein is the macro to anchor everything else around. A general educational range cited in nutrition literature is roughly 1.2–1.6 g of protein per kg of body weight per day to support muscle preservation during weight loss. These are population-level reference ranges, not a personal prescription — your own needs depend on factors your healthcare professional knows best.

Step 4 — Divide remaining calories between carbs and fat

Once protein is set, the remaining calorie budget is split between carbohydrate and fat according to preference and tolerance. A simple approach many people use is roughly 30% fat and the remainder from carbohydrate, but this is highly individual. What matters most is hitting your protein and calorie targets consistently. You can also track how your weight loss percentage changes over time as you dial in your macros.

• Protein: prioritise this — aim for your per-kg target each day
• Fat: do not go too low; healthy fats support hormones and satiety
• Carbohydrate: fill the remaining calories; fibre-rich sources tend to sit better on GLP-1 medicines

Working out your macros on paper is straightforward; hitting them consistently every day is the harder part — especially when appetite is suppressed and meals feel like a chore. GLP Trackr's AI food photo scan is the fastest way to close that gap: point your camera at a plate and the app returns an instant breakdown of calories, protein, carbs, and fat without manual entry.

Once your targets are set inside the app, you can see at a glance how each meal moves you toward your protein and calorie goals for the day. The barcode scanner and food search cover packaged foods and drinks, while the meal plan library surfaces GLP-1-friendly recipes designed around higher protein and gentle-on-the-stomach ingredients — useful on days when deciding what to eat feels overwhelming.

Because GLP Trackr also logs your weight and daily check-ins, you get to see how consistently hitting your macro targets relates to how your weight moves over time — the kind of insight that is genuinely hard to spot without tracking. If you are curious how your dose schedule connects to appetite and food intake patterns, our guide on understanding your Wegovy dose may also be useful context.

General macro ranges are a helpful starting point, but your personal targets should be shaped by your own circumstances. If you are unsure what numbers are right for you, your prescriber or doctor or a registered dietitian is the right person to ask — GLP Trackr gives you the data to have that conversation, not a substitute for it.

Ready to put your macro targets into practice? Download GLP Trackr on the App Store or Google Play and get your first 7 days free — snap a photo of your next meal and see how effortlessly the numbers add up.